2QFD: Crystal Structure Of The Regulatory Domain Of Human Rig-I With Bound Hg

Citation:
Abstract
The ATPase RIG-I senses viral RNAs that contain 5'-triphosphates in the cytoplasm. It initiates a signaling cascade that activates innate immune response by interferon and cytokine production, providing essential antiviral protection for the host. The mode of RNA 5'-triphosphate sensing by RIG-I remains elusive. We show that the C-terminal regulatory domain RD of RIG-I binds viral RNA in a 5'-triphosphate-dependent manner and activates the RIG-I ATPase by RNA-dependent dimerization. The crystal structure of RD reveals a zinc-binding domain that is structurally related to GDP/GTP exchange factors of Rab-like GTPases. The zinc coordination site is essential for RIG-I signaling and is also conserved in MDA5 and LGP2, suggesting related RD domains in all three enzymes. Structure-guided mutagenesis identifies a positively charged groove as likely 5'-triphosphate-binding site of RIG-I. This groove is distinct in MDA5 and LGP2, raising the possibility that RD confers ligand specificity.
PDB ID: 2QFDDownload
MMDB ID: 62364
PDB Deposition Date: 2007/6/27
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 2.7  Å
Source Organism:
Similar Structures:
Biological Unit for 2QFD: monomeric; determined by author and by software (PISA)
Molecular Components in 2QFD
Label Count Molecule
Protein (1 molecule)
1
Probable Atp-dependent RNA Helicase Ddx58(Gene symbol: DDX58)
Molecule annotation
Chemical (1 molecule)
1
1
* Click molecule labels to explore molecular sequence information.

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